COMPOSER ARTFULLY MIXES A SYMPHONY OF ELECTRONIC SOUND

Robert WolfCHICAGO TRIBUNE

When Howard Sandroff performs, all he normally needs are two small packages containing a floppy disc with voice data and score, his synthesizers and computer (as long as the concert stage has a sound system).

Ten years ago, if he wanted to give a performance, he would have had to haul around three walls of analog synthesizers.

Sandroff is a composer and performer of electronic music, as well as director of the Electronic Music Studio at the University of Chicago. He bristles at the suggestion that a performer of electronic music might be just a mechanic.

''It used to be that way, but it has become a very artful sort of experience. There are really only a few people around the country who specialize in live performance, and I am one of them. And it`s because you can manipulate these systems in real time, change them in real time, that it becomes like an instrument. Not necessarily this system, but others.''

But just what is it that transforms a seemingly mechanical process into art? In ''The Tempest,'' for which he programmed and performed the electronic music for John Eaton`s opera at the Santa Fe Opera last summer, ''I was playing in the same way'' a musician does, he says. ''It`s just that I wasn`t scraping strings or blowing into tubes. I was pushing buttons. I had to do them from a musical score.''

For one, he had to follow the conductor`s tempo, which could vary between performances. That meant Sandroff had to alter the tempo that composer John Eaton had programmed.

For another, he had to process the sounds of instruments and, in one case, a singer`s voice. The singer had a wireless mike that transmitted the audio to a phase vocoder. Not only was the singer`s voice heard, but the phase vocoder redesigned the audio so that it came out sounding like another female voice, singing at varied and different intervals. That meant, Sandroff says, ''I actually played her voice on the keyboard.

''Anybody who involves themselves in a live electronic music performance certainly has to be musical. You have to program it.''

In short, the performer of electronic music has to design the instruments and determine how they will articulate the sounds. Those are the same performance decisions that a musician or a conductor makes. Occasionally electronic performers make decisions during a performance, but usually their decisions are made beforehand. The difference between the times acoustic and electronic performers make their decisions is, in Sandroff`s mind, the only crucial distinction between the two.

Sandroff believes that poor performance decisions may be partially responsible for some of the adverse criticism electronic music--or most contemporary music for that matter--receives.

''If Beethoven had been played as badly in his day as contemporary composers are,'' Sandroff says, ''he wouldn`t be played today.'' Adverse criticism to electronic music also comes, he says, from those who simply have an aversion to the technology.

Still other complaints come from composers and musicians who think these systems sound mechanical. ''Or that somehow or other there isn`t soul there. That`s ridiculous. I`m a musician. I program them. Once you reach a certain level (of proficiency), these instruments are capable of playing and making sounds with as much soul as I can put in them. If I am the composer and the performer, it`s all my soul.''

Composing with these systems, he says, differs in three ways from traditional methods of composition. One, the composer of electronic music can get instant feedback, whereas a composer for conventional, acoustic instruments can wait years to hear his work performed. Two, if acoustic instrumentalists don`t play a piece well at its premiere, that premiere may be the composition`s last performance. Three, a poor performance won`t tell the composer if his piece worked. All of these possibilities, he says, slow an artist`s growth and encourage safe musical activities.

He says that by working solely with computer and synthesizer, the composer-performer ''misses that rich collaboration between composer and performer.''

Sandroff begins composing by writing a musicial line and then determining what should play it.

''I learned most about sound by listening to instruments and people playing them. I always strive for sort of an acoustic model.''

He does not, however, want his sounds to be imitations of particular instruments. That partly explains why Sandroff, who also writes for acoustic instruments, composes for computers. He is not limited by the sounds of instruments and by the ability of the musicians playing them. ''The only thing I`m limited by is my own imagination.''

Like many composers, Sandroff uses Yamaha DX7s, which are keyboard operated, digitally controlled synthesizers. The large number of pop musicians wanting synthesizers brought the price within Sandroff`s reach.

''I knew it would happen someday. In the last three years I`ve seen this stuff blossom. You can buy this thing right here for less than $5,000. Ten years ago you couldn`t have bought it for a million dollars.''

Twenty years ago composers of electronic music were using analog synthesizers, which also had keyboards. Basicially, the difference between the two systems is that the analog synthesizer deals with electrical current as if it were analogous to sound. Digital synthesizers, like the Yamaha, manipulate numbers that will eventually become sound.

Because the computer deals with ''very, very specific quantized instructions and analog synthesis deals with the changes in electrical conditions, the two are simply not compatible in many ways. You need some method of converting from one to the other. I now think I can revive some of this technology and use it with the computer.''

He wants to do this, especially to take advantage of some of the random qualities the analog synthesizer offers.

Sandroff now works with the equivalent of eight Yamaha DX7 synthesizers, an Apple II, a keyboard, a mixing console, a custom Serge analog system and a Yamaha digital sequencer model OX1.

The sequencer-computer controls the synthesizers, each of which has the capacity to store 32 individual ''voices'' or sounds. ''The sequencer makes no sound itself. It`s just a set of switches and generates a particular type of code,'' he says. That code tells the synthesizer what pitch to play, when to play it and whether to play it loudly or softly.

''The whole process (of composition) starts with first designing a voice, designing a sound. And that`s what I use the Apple computer for. It provides a window into the synthesizer,'' he says.

That ''window'' is the monitor, which displays six boxes, each with a number. ''Each one of these boxes represents a theoretical sound-producing device called an oscillator. I say it`s theoretical because it`s not really sound, it`s just numbers,'' he says. ''Essentially what it is is mathematical tables that define a particular wave shape.'' To change the sound--to make it richer or fuzzier or whatever--you change the number. That alters the slope, the curve of the line.

The final work on a piece, adjusting the balance, is done with the mixing console.

Sandroff directs the New Art Ensemble, a 7-year-old chamber ensemble consisting of himself and a variety of instrumentalists, whose number depends on the works performed.

From July 14-25 Sandroff will lead a seminar at the University of Chicago on computer applications in music for composers, performers and educators. The FM Synthesis/Midi Seminar, as it is called, makes use of the Yamaha computer- assisted music system. For information, call 962-1722.